Crystal Structure of Nonstoichiometric Copper-Substituted La(Ni1−zCuz)x Compounds Studied by Neutron and Synchrotron Anomalous Powder Diffraction
✍ Scribed by M. Latroche; J.-M. Joubert; A. Percheron-Guégan; P.H.L. Notten
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 474 KB
- Volume
- 146
- Category
- Article
- ISSN
- 0022-4596
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✦ Synopsis
The structural properties of the potential battery electrode materials LaNi 4 Cu, LaNi 4.4 Cu, LaNi 5 Cu, and LaNi 4.5 Cu 1.5 have been investigated by neutron and anomalous synchrotron powder di4raction. The nonstoichiometry of such AB x (54x46) compounds has been described in a structure derived from the hexagonal CaCu 5 -type structure by replacement of the A atoms by dumbbells of B atoms. In these copper-substituted compounds, Cu can occupy any of the four available nickel sites. From a joint re5nement procedure using both neutron and synchrotron data, the copper-to-nickel ratio at each B site has been determined. This shows that substitution is not random and that copper occupies some crystallographic sites preferentially. The results are discussed and compared to other substituted AB 5 systems.